验证if语句中的字符串，但补偿拼写错误

I'm in the process of creating a conditional if statement to display certain data if information is input into a text field.. The only block i've encountered is possible user-error.. So i'm wondering if theres a way to compensate for spelling mistakes?

if (isset($_POST['Data_Cont'])){
    if ($_POST['Data_Cont'] === "Alpha239d"){
        echo "Displaying Form Specific Data"; 
    }
}

But how to compensate for spelling mistakes?

Three possibles:

1) Use a dropdown of available options rather than a text input.

2) Make arrays of exact and near match strings and use in_array rather than === for the conditional statement

3) Use the levenshtein function in the conditional statement allowing for a set number of differences in the string compared to what is expected, however this may give false positives depending on how close different words you are expecting are to each other